From: tb <tb@openbsd.org>
Date: Sat, 2 Jul 2022 16:00:12 +0000 (+0000)
Subject: Rename uses 'curve' to 'group' and rework tls1 group API.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=c5270c5dfaf8fffd3edfe2baaecf04b16544a7ea;p=openbsd

Rename uses 'curve' to 'group' and rework tls1 group API.

This reworks various tls1_ curve APIs to indicate success via a boolean
return value and move the output to an out parameter. This makes the
caller code easier and more consistent.

Based on a suggestion by jsing

ok jsing
---

diff --git a/lib/libssl/s3_lib.c b/lib/libssl/s3_lib.c
index 4575a141cf8..cfd50e66be3 100644
--- a/lib/libssl/s3_lib.c
+++ b/lib/libssl/s3_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s3_lib.c,v 1.233 2022/06/29 21:18:04 tb Exp $ */
+/* $OpenBSD: s3_lib.c,v 1.234 2022/07/02 16:00:12 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -2494,13 +2494,13 @@ ssl3_choose_cipher(SSL *s, STACK_OF(SSL_CIPHER) *clnt,
 	STACK_OF(SSL_CIPHER) *prio, *allow;
 	SSL_CIPHER *c, *ret = NULL;
 	int can_use_ecc;
-	int i, ii, ok;
+	int i, ii, nid, ok;
 	SSL_CERT *cert;
 
 	/* Let's see which ciphers we can support */
 	cert = s->cert;
 
-	can_use_ecc = (tls1_get_shared_curve(s) != NID_undef);
+	can_use_ecc = tls1_get_supported_group(s, &nid);
 
 	/*
 	 * Do not set the compare functions, because this may lead to a
diff --git a/lib/libssl/ssl_clnt.c b/lib/libssl/ssl_clnt.c
index 604b55277cf..8fe416b74a5 100644
--- a/lib/libssl/ssl_clnt.c
+++ b/lib/libssl/ssl_clnt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_clnt.c,v 1.149 2022/06/30 11:17:49 tb Exp $ */
+/* $OpenBSD: ssl_clnt.c,v 1.150 2022/07/02 16:00:12 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1271,13 +1271,13 @@ static int
 ssl3_get_server_kex_ecdhe(SSL *s, CBS *cbs)
 {
 	uint8_t curve_type;
-	uint16_t curve_id;
+	uint16_t group_id;
 	int decode_error;
 	CBS public;
 
 	if (!CBS_get_u8(cbs, &curve_type))
 		goto decode_err;
-	if (!CBS_get_u16(cbs, &curve_id))
+	if (!CBS_get_u16(cbs, &group_id))
 		goto decode_err;
 
 	/* Only named curves are supported. */
@@ -1291,17 +1291,17 @@ ssl3_get_server_kex_ecdhe(SSL *s, CBS *cbs)
 		goto decode_err;
 
 	/*
-	 * Check that the curve is one of our preferences - if it is not,
-	 * the server has sent us an invalid curve.
+	 * Check that the group is one of our preferences - if it is not,
+	 * the server has sent us an invalid group.
 	 */
-	if (!tls1_check_curve(s, curve_id)) {
+	if (!tls1_check_group(s, group_id)) {
 		SSLerror(s, SSL_R_WRONG_CURVE);
 		ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
 		goto err;
 	}
 
 	tls_key_share_free(s->s3->hs.key_share);
-	if ((s->s3->hs.key_share = tls_key_share_new(curve_id)) == NULL)
+	if ((s->s3->hs.key_share = tls_key_share_new(group_id)) == NULL)
 		goto err;
 
 	if (!tls_key_share_peer_public(s->s3->hs.key_share, &public,
diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index d3e600b6b76..a2ca99c02d7 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.409 2022/06/30 16:05:07 tb Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.410 2022/07/02 16:00:12 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1306,7 +1306,7 @@ int ssl_security_cert(const SSL_CTX *ctx, const SSL *ssl, X509 *x509,
     int is_peer, int *out_error);
 int ssl_security_cert_chain(const SSL *ssl, STACK_OF(X509) *sk,
     X509 *x509, int *out_error);
-int ssl_security_supported_group(const SSL *ssl, uint16_t curve_id);
+int ssl_security_supported_group(const SSL *ssl, uint16_t group_id);
 
 int ssl_get_new_session(SSL *s, int session);
 int ssl_get_prev_session(SSL *s, CBS *session_id, CBS *ext_block,
@@ -1515,11 +1515,11 @@ int tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len,
 int tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len,
     const char *groups);
 
-int tls1_ec_curve_id2nid(const uint16_t curve_id);
-int tls1_ec_curve_id2bits(const uint16_t curve_id);
-uint16_t tls1_ec_nid2curve_id(const int nid);
-int tls1_check_curve(SSL *s, const uint16_t group_id);
-int tls1_get_shared_curve(SSL *s);
+int tls1_ec_group_id2nid(uint16_t group_id, int *out_nid);
+int tls1_ec_group_id2bits(uint16_t group_id, int *out_bits);
+int tls1_ec_nid2group_id(int nid, uint16_t *out_group_id);
+int tls1_check_group(SSL *s, uint16_t group_id);
+int tls1_get_supported_group(SSL *s, int *group_nid);
 
 int ssl_check_clienthello_tlsext_early(SSL *s);
 int ssl_check_clienthello_tlsext_late(SSL *s);
diff --git a/lib/libssl/ssl_seclevel.c b/lib/libssl/ssl_seclevel.c
index 35f8b8891b2..2e0b74141f7 100644
--- a/lib/libssl/ssl_seclevel.c
+++ b/lib/libssl/ssl_seclevel.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ssl_seclevel.c,v 1.14 2022/06/30 16:05:07 tb Exp $ */
+/*	$OpenBSD: ssl_seclevel.c,v 1.15 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2020 Theo Buehler <tb@openbsd.org>
  *
@@ -401,23 +401,23 @@ ssl_security_cert_chain(const SSL *ssl, STACK_OF(X509) *sk, X509 *x509,
 }
 
 int
-ssl_security_supported_group(const SSL *ssl, uint16_t curve_id)
+ssl_security_supported_group(const SSL *ssl, uint16_t group_id)
 {
 	CBB cbb;
 	int bits, nid;
-	uint8_t curve[2];
+	uint8_t group[2];
 
-	if ((bits = tls1_ec_curve_id2bits(curve_id)) == 0)
+	if (!tls1_ec_group_id2bits(group_id, &bits))
 		return 0;
-	if ((nid = tls1_ec_curve_id2nid(curve_id)) == NID_undef)
+	if (!tls1_ec_group_id2nid(group_id, &nid))
 		return 0;
 
-	if (!CBB_init_fixed(&cbb, curve, sizeof(curve)))
+	if (!CBB_init_fixed(&cbb, group, sizeof(group)))
 		return 0;
-	if (!CBB_add_u16(&cbb, curve_id))
+	if (!CBB_add_u16(&cbb, group_id))
 		return 0;
 	if (!CBB_finish(&cbb, NULL, NULL))
 		return 0;
 
-	return ssl_security(ssl, SSL_SECOP_CURVE_SUPPORTED, bits, nid, curve);
+	return ssl_security(ssl, SSL_SECOP_CURVE_SUPPORTED, bits, nid, group);
 }
diff --git a/lib/libssl/ssl_sigalgs.c b/lib/libssl/ssl_sigalgs.c
index 9c38a076ac8..754d76e72a2 100644
--- a/lib/libssl/ssl_sigalgs.c
+++ b/lib/libssl/ssl_sigalgs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_sigalgs.c,v 1.45 2022/06/29 07:55:59 tb Exp $ */
+/* $OpenBSD: ssl_sigalgs.c,v 1.46 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2018-2020 Bob Beck <beck@openbsd.org>
  * Copyright (c) 2021 Joel Sing <jsing@openbsd.org>
@@ -39,7 +39,7 @@ const struct ssl_sigalg sigalgs[] = {
 		.key_type = EVP_PKEY_EC,
 		.md = EVP_sha512,
 		.security_level = 5,
-		.curve_nid = NID_secp521r1,
+		.group_nid = NID_secp521r1,
 	},
 #ifndef OPENSSL_NO_GOST
 	{
@@ -60,7 +60,7 @@ const struct ssl_sigalg sigalgs[] = {
 		.key_type = EVP_PKEY_EC,
 		.md = EVP_sha384,
 		.security_level = 4,
-		.curve_nid = NID_secp384r1,
+		.group_nid = NID_secp384r1,
 	},
 	{
 		.value = SIGALG_RSA_PKCS1_SHA256,
@@ -73,7 +73,7 @@ const struct ssl_sigalg sigalgs[] = {
 		.key_type = EVP_PKEY_EC,
 		.md = EVP_sha256,
 		.security_level = 3,
-		.curve_nid = NID_X9_62_prime256v1,
+		.group_nid = NID_X9_62_prime256v1,
 	},
 #ifndef OPENSSL_NO_GOST
 	{
@@ -321,12 +321,12 @@ ssl_sigalg_pkey_ok(SSL *s, const struct ssl_sigalg *sigalg, EVP_PKEY *pkey)
 	    (sigalg->flags & SIGALG_FLAG_RSA_PSS) == 0)
 		return 0;
 
-	/* Ensure that curve matches for EC keys. */
+	/* Ensure that group matches for EC keys. */
 	if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
-		if (sigalg->curve_nid == 0)
+		if (sigalg->group_nid == 0)
 			return 0;
 		if (EC_GROUP_get_curve_name(EC_KEY_get0_group(
-		    EVP_PKEY_get0_EC_KEY(pkey))) != sigalg->curve_nid)
+		    EVP_PKEY_get0_EC_KEY(pkey))) != sigalg->group_nid)
 			return 0;
 	}
 
diff --git a/lib/libssl/ssl_sigalgs.h b/lib/libssl/ssl_sigalgs.h
index 5be2122906a..21a54d642bc 100644
--- a/lib/libssl/ssl_sigalgs.h
+++ b/lib/libssl/ssl_sigalgs.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_sigalgs.h,v 1.25 2022/06/29 07:53:58 tb Exp $ */
+/* $OpenBSD: ssl_sigalgs.h,v 1.26 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2018-2019 Bob Beck <beck@openbsd.org>
  *
@@ -65,7 +65,7 @@ struct ssl_sigalg {
 	int key_type;
 	const EVP_MD *(*md)(void);
 	int security_level;
-	int curve_nid;
+	int group_nid;
 	int flags;
 };
 
diff --git a/lib/libssl/ssl_srvr.c b/lib/libssl/ssl_srvr.c
index 8f110831e49..526d9e678b2 100644
--- a/lib/libssl/ssl_srvr.c
+++ b/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.146 2022/06/30 11:17:50 tb Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.147 2022/07/02 16:00:12 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1380,7 +1380,7 @@ ssl3_send_server_kex_ecdhe(SSL *s, CBB *cbb)
 	CBB public;
 	int nid;
 
-	if ((nid = tls1_get_shared_curve(s)) == NID_undef) {
+	if (!tls1_get_supported_group(s, &nid)) {
 		SSLerror(s, SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
 		ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
 		goto err;
diff --git a/lib/libssl/ssl_tlsext.c b/lib/libssl/ssl_tlsext.c
index 88d26fd326b..74579255724 100644
--- a/lib/libssl/ssl_tlsext.c
+++ b/lib/libssl/ssl_tlsext.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.c,v 1.117 2022/06/30 16:05:07 tb Exp $ */
+/* $OpenBSD: ssl_tlsext.c,v 1.118 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2016, 2017, 2019 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -1516,7 +1516,7 @@ tlsext_keyshare_server_parse(SSL *s, uint16_t msg_type, CBS *cbs, int *alert)
 			continue;
 
 		/* XXX - consider implementing server preference. */
-		if (!tls1_check_curve(s, group))
+		if (!tls1_check_group(s, group))
 			continue;
 
 		/* Decode and store the selected key share. */
diff --git a/lib/libssl/t1_lib.c b/lib/libssl/t1_lib.c
index 97489012683..beaaae1eb0c 100644
--- a/lib/libssl/t1_lib.c
+++ b/lib/libssl/t1_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: t1_lib.c,v 1.190 2022/07/02 15:53:37 tb Exp $ */
+/* $OpenBSD: t1_lib.c,v 1.191 2022/07/02 16:00:12 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -150,12 +150,16 @@ tls1_clear(SSL *s)
 	s->version = s->method->version;
 }
 
-struct curve {
+struct supported_group {
 	int nid;
 	int bits;
 };
 
-static const struct curve nid_list[] = {
+/*
+ * Supported groups (formerly known as named curves)
+ * https://www.iana.org/assignments/tls-parameters/#tls-parameters-8
+ */
+static const struct supported_group nid_list[] = {
 	[1] = {
 		.nid = NID_sect163k1,
 		.bits = 80,
@@ -274,6 +278,8 @@ static const struct curve nid_list[] = {
 	},
 };
 
+#define NID_LIST_LEN (sizeof(nid_list) / sizeof(nid_list[0]))
+
 #if 0
 static const uint8_t ecformats_list[] = {
 	TLSEXT_ECPOINTFORMAT_uncompressed,
@@ -287,7 +293,7 @@ static const uint8_t ecformats_default[] = {
 };
 
 #if 0
-static const uint16_t eccurves_list[] = {
+static const uint16_t ecgroups_list[] = {
 	29,			/* X25519 (29) */
 	14,			/* sect571r1 (14) */
 	13,			/* sect571k1 (13) */
@@ -320,116 +326,155 @@ static const uint16_t eccurves_list[] = {
 };
 #endif
 
-static const uint16_t eccurves_client_default[] = {
+static const uint16_t ecgroups_client_default[] = {
 	29,			/* X25519 (29) */
 	23,			/* secp256r1 (23) */
 	24,			/* secp384r1 (24) */
 	25,			/* secp521r1 (25) */
 };
 
-static const uint16_t eccurves_server_default[] = {
+static const uint16_t ecgroups_server_default[] = {
 	29,			/* X25519 (29) */
 	23,			/* secp256r1 (23) */
 	24,			/* secp384r1 (24) */
 };
 
 int
-tls1_ec_curve_id2nid(const uint16_t curve_id)
+tls1_ec_group_id2nid(uint16_t group_id, int *out_nid)
 {
-	const struct curve *curve;
+	const struct supported_group *group;
 
-	/* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
-	if ((curve_id < 1) ||
-	    ((unsigned int)curve_id >= sizeof(nid_list) / sizeof(nid_list[0])))
-		return NID_undef;
+	if (group_id < 1 || group_id >= NID_LIST_LEN)
+		return 0;
+
+	if ((group = &nid_list[group_id]) == NULL)
+		return 0;
 
-	if ((curve = &nid_list[curve_id]) == NULL)
-		return NID_undef;
+	*out_nid = group->nid;
 
-	return curve->nid;
+	return 1;
 }
 
 int
-tls1_ec_curve_id2bits(const uint16_t curve_id)
+tls1_ec_group_id2bits(uint16_t group_id, int *out_bits)
 {
-	const struct curve *curve;
+	const struct supported_group *group;
 
-	if ((curve_id < 1) ||
-	    ((unsigned int)curve_id >= sizeof(nid_list) / sizeof(nid_list[0])))
+	if (group_id < 1 || group_id >= NID_LIST_LEN)
 		return 0;
 
-	if ((curve = &nid_list[curve_id]) == NULL)
+	if ((group = &nid_list[group_id]) == NULL)
 		return 0;
 
-	return curve->bits;
+	*out_bits = group->bits;
+
+	return 1;
 }
 
-uint16_t
-tls1_ec_nid2curve_id(const int nid)
+int
+tls1_ec_nid2group_id(const int nid, uint16_t *out_group_id)
 {
-	/* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
+	uint16_t group_id;
+
 	switch (nid) {
-	case NID_sect163k1: /* sect163k1 (1) */
-		return 1;
-	case NID_sect163r1: /* sect163r1 (2) */
-		return 2;
-	case NID_sect163r2: /* sect163r2 (3) */
-		return 3;
-	case NID_sect193r1: /* sect193r1 (4) */
-		return 4;
-	case NID_sect193r2: /* sect193r2 (5) */
-		return 5;
-	case NID_sect233k1: /* sect233k1 (6) */
-		return 6;
-	case NID_sect233r1: /* sect233r1 (7) */
-		return 7;
-	case NID_sect239k1: /* sect239k1 (8) */
-		return 8;
-	case NID_sect283k1: /* sect283k1 (9) */
-		return 9;
-	case NID_sect283r1: /* sect283r1 (10) */
-		return 10;
-	case NID_sect409k1: /* sect409k1 (11) */
-		return 11;
-	case NID_sect409r1: /* sect409r1 (12) */
-		return 12;
-	case NID_sect571k1: /* sect571k1 (13) */
-		return 13;
-	case NID_sect571r1: /* sect571r1 (14) */
-		return 14;
-	case NID_secp160k1: /* secp160k1 (15) */
-		return 15;
-	case NID_secp160r1: /* secp160r1 (16) */
-		return 16;
-	case NID_secp160r2: /* secp160r2 (17) */
-		return 17;
-	case NID_secp192k1: /* secp192k1 (18) */
-		return 18;
-	case NID_X9_62_prime192v1: /* secp192r1 (19) */
-		return 19;
-	case NID_secp224k1: /* secp224k1 (20) */
-		return 20;
-	case NID_secp224r1: /* secp224r1 (21) */
-		return 21;
-	case NID_secp256k1: /* secp256k1 (22) */
-		return 22;
-	case NID_X9_62_prime256v1: /* secp256r1 (23) */
-		return 23;
-	case NID_secp384r1: /* secp384r1 (24) */
-		return 24;
-	case NID_secp521r1: /* secp521r1 (25) */
-		return 25;
-	case NID_brainpoolP256r1: /* brainpoolP256r1 (26) */
-		return 26;
-	case NID_brainpoolP384r1: /* brainpoolP384r1 (27) */
-		return 27;
-	case NID_brainpoolP512r1: /* brainpoolP512r1 (28) */
-		return 28;
-	case NID_X25519:		/* X25519 (29) */
-		return 29;
+	case NID_sect163k1:
+		group_id = 1;
+		break;
+	case NID_sect163r1:
+		group_id = 2;
+		break;
+	case NID_sect163r2:
+		group_id = 3;
+		break;
+	case NID_sect193r1:
+		group_id = 4;
+		break;
+	case NID_sect193r2:
+		group_id = 5;
+		break;
+	case NID_sect233k1:
+		group_id = 6;
+		break;
+	case NID_sect233r1:
+		group_id = 7;
+		break;
+	case NID_sect239k1:
+		group_id = 8;
+		break;
+	case NID_sect283k1:
+		group_id = 9;
+		break;
+	case NID_sect283r1:
+		group_id = 10;
+		break;
+	case NID_sect409k1:
+		group_id = 11;
+		break;
+	case NID_sect409r1:
+		group_id = 12;
+		break;
+	case NID_sect571k1:
+		group_id = 13;
+		break;
+	case NID_sect571r1:
+		group_id = 14;
+		break;
+	case NID_secp160k1:
+		group_id = 15;
+		break;
+	case NID_secp160r1:
+		group_id = 16;
+		break;
+	case NID_secp160r2:
+		group_id = 17;
+		break;
+	case NID_secp192k1:
+		group_id = 18;
+		break;
+	case NID_X9_62_prime192v1: /* aka secp192r1 */
+		group_id = 19;
+		break;
+	case NID_secp224k1:
+		group_id = 20;
+		break;
+	case NID_secp224r1:
+		group_id = 21;
+		break;
+	case NID_secp256k1:
+		group_id = 22;
+		break;
+	case NID_X9_62_prime256v1: /* aka secp256r1 */
+		group_id = 23;
+		break;
+	case NID_secp384r1:
+		group_id = 24;
+		break;
+	case NID_secp521r1:
+		group_id = 25;
+		break;
+	case NID_brainpoolP256r1:
+		group_id = 26;
+		break;
+	case NID_brainpoolP384r1:
+		group_id = 27;
+		break;
+	case NID_brainpoolP512r1:
+		group_id = 28;
+		break;
+	case NID_X25519:
+		group_id = 29;
+		break;
 	default:
-		return 0;
+		group_id = 0;
+		break;
 	}
+
+	if (group_id == 0)
+		return 0;
+
+	*out_group_id = group_id;
+
+	return 1;
 }
 
 /*
@@ -476,11 +521,11 @@ tls1_get_group_list(SSL *s, int client_groups, const uint16_t **pgroups,
 		return;
 
 	if (!s->server) {
-		*pgroups = eccurves_client_default;
-		*pgroupslen = sizeof(eccurves_client_default) / 2;
+		*pgroups = ecgroups_client_default;
+		*pgroupslen = sizeof(ecgroups_client_default) / 2;
 	} else {
-		*pgroups = eccurves_server_default;
-		*pgroupslen = sizeof(eccurves_server_default) / 2;
+		*pgroups = ecgroups_server_default;
+		*pgroupslen = sizeof(ecgroups_server_default) / 2;
 	}
 }
 
@@ -491,13 +536,11 @@ tls1_set_groups(uint16_t **out_group_ids, size_t *out_group_ids_len,
 	uint16_t *group_ids;
 	size_t i;
 
-	group_ids = calloc(ngroups, sizeof(uint16_t));
-	if (group_ids == NULL)
+	if ((group_ids = calloc(ngroups, sizeof(uint16_t))) == NULL)
 		return 0;
 
 	for (i = 0; i < ngroups; i++) {
-		group_ids[i] = tls1_ec_nid2curve_id(groups[i]);
-		if (group_ids[i] == 0) {
+		if (!tls1_ec_nid2group_id(groups[i], &group_ids[i])) {
 			free(group_ids);
 			return 0;
 		}
@@ -537,8 +580,7 @@ tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len,
 			goto err;
 		group_ids = new_group_ids;
 
-		group_ids[ngroups] = tls1_ec_nid2curve_id(nid);
-		if (group_ids[ngroups] == 0)
+		if (!tls1_ec_nid2group_id(nid, &group_ids[ngroups]))
 			goto err;
 
 		ngroups++;
@@ -558,9 +600,9 @@ tls1_set_group_list(uint16_t **out_group_ids, size_t *out_group_ids_len,
 	return 0;
 }
 
-/* Check that a curve is one of our preferences. */
+/* Check that a group is one of our preferences. */
 int
-tls1_check_curve(SSL *s, const uint16_t curve_id)
+tls1_check_group(SSL *s, uint16_t group_id)
 {
 	const uint16_t *groups;
 	size_t groupslen, i;
@@ -570,14 +612,14 @@ tls1_check_curve(SSL *s, const uint16_t curve_id)
 	for (i = 0; i < groupslen; i++) {
 		if (!ssl_security_supported_group(s, groups[i]))
 			continue;
-		if (groups[i] == curve_id)
-			return (1);
+		if (groups[i] == group_id)
+			return 1;
 	}
-	return (0);
+	return 0;
 }
 
 int
-tls1_get_shared_curve(SSL *s)
+tls1_get_supported_group(SSL *s, int *out_nid)
 {
 	size_t preflen, supplen, i, j;
 	const uint16_t *pref, *supp;
@@ -585,9 +627,9 @@ tls1_get_shared_curve(SSL *s)
 
 	/* Cannot do anything on the client side. */
 	if (s->server == 0)
-		return (NID_undef);
+		return 0;
 
-	/* Return first preference shared curve. */
+	/* Return first preference supported group. */
 	server_pref = (s->internal->options & SSL_OP_CIPHER_SERVER_PREFERENCE);
 	tls1_get_group_list(s, (server_pref == 0), &pref, &preflen);
 	tls1_get_group_list(s, (server_pref != 0), &supp, &supplen);
@@ -597,15 +639,15 @@ tls1_get_shared_curve(SSL *s)
 			continue;
 		for (j = 0; j < supplen; j++) {
 			if (pref[i] == supp[j])
-				return (tls1_ec_curve_id2nid(pref[i]));
+				return tls1_ec_group_id2nid(pref[i], out_nid);
 		}
 	}
-	return (NID_undef);
+	return 0;
 }
 
 /* For an EC key set TLS ID and required compression based on parameters. */
 static int
-tls1_set_ec_id(uint16_t *curve_id, uint8_t *comp_id, EC_KEY *ec)
+tls1_set_ec_id(uint16_t *group_id, uint8_t *comp_id, EC_KEY *ec)
 {
 	const EC_GROUP *grp;
 	const EC_METHOD *meth;
@@ -615,18 +657,18 @@ tls1_set_ec_id(uint16_t *curve_id, uint8_t *comp_id, EC_KEY *ec)
 	if (ec == NULL)
 		return (0);
 
-	/* Determine whether the curve is defined over a prime field. */
+	/* Determine whether the group is defined over a prime field. */
 	if ((grp = EC_KEY_get0_group(ec)) == NULL)
 		return (0);
 	if ((meth = EC_GROUP_method_of(grp)) == NULL)
 		return (0);
 	prime_field = (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field);
 
-	/* Determine curve ID - NID_undef results in a curve ID of zero. */
+	/* Determine group ID. */
 	nid = EC_GROUP_get_curve_name(grp);
-	/* If we have an ID set it, otherwise set arbitrary explicit curve. */
-	if ((*curve_id = tls1_ec_nid2curve_id(nid)) == 0)
-		*curve_id = prime_field ? 0xff01 : 0xff02;
+	/* If we have an ID set it, otherwise set arbitrary explicit group. */
+	if (!tls1_ec_nid2group_id(nid, group_id))
+		*group_id = prime_field ? 0xff01 : 0xff02;
 
 	if (comp_id == NULL)
 		return (1);
@@ -646,7 +688,7 @@ tls1_set_ec_id(uint16_t *curve_id, uint8_t *comp_id, EC_KEY *ec)
 
 /* Check that an EC key is compatible with extensions. */
 static int
-tls1_check_ec_key(SSL *s, const uint16_t *curve_id, const uint8_t *comp_id)
+tls1_check_ec_key(SSL *s, const uint16_t *group_id, const uint8_t *comp_id)
 {
 	size_t groupslen, formatslen, i;
 	const uint16_t *groups;
@@ -667,12 +709,12 @@ tls1_check_ec_key(SSL *s, const uint16_t *curve_id, const uint8_t *comp_id)
 	}
 
 	/*
-	 * Check curve list if present, otherwise everything is supported.
+	 * Check group list if present, otherwise everything is supported.
 	 */
 	tls1_get_group_list(s, 1, &groups, &groupslen);
-	if (curve_id != NULL && groups != NULL) {
+	if (group_id != NULL && groups != NULL) {
 		for (i = 0; i < groupslen; i++) {
-			if (groups[i] == *curve_id)
+			if (groups[i] == *group_id)
 				break;
 		}
 		if (i == groupslen)
@@ -687,7 +729,7 @@ int
 tls1_check_ec_server_key(SSL *s)
 {
 	SSL_CERT_PKEY *cpk = s->cert->pkeys + SSL_PKEY_ECC;
-	uint16_t curve_id;
+	uint16_t group_id;
 	uint8_t comp_id;
 	EC_KEY *eckey;
 	EVP_PKEY *pkey;
@@ -698,10 +740,10 @@ tls1_check_ec_server_key(SSL *s)
 		return (0);
 	if ((eckey = EVP_PKEY_get0_EC_KEY(pkey)) == NULL)
 		return (0);
-	if (!tls1_set_ec_id(&curve_id, &comp_id, eckey))
+	if (!tls1_set_ec_id(&group_id, &comp_id, eckey))
 		return (0);
 
-	return tls1_check_ec_key(s, &curve_id, &comp_id);
+	return tls1_check_ec_key(s, &group_id, &comp_id);
 }
 
 int
diff --git a/lib/libssl/tls13_client.c b/lib/libssl/tls13_client.c
index 11eb880a6ef..fb2dd69eb22 100644
--- a/lib/libssl/tls13_client.c
+++ b/lib/libssl/tls13_client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_client.c,v 1.94 2022/02/03 16:33:12 jsing Exp $ */
+/* $OpenBSD: tls13_client.c,v 1.95 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2018, 2019 Joel Sing <jsing@openbsd.org>
  *
@@ -440,7 +440,7 @@ tls13_client_hello_retry_send(struct tls13_ctx *ctx, CBB *cbb)
 	 * supported groups and is not the same as the key share we previously
 	 * offered.
 	 */
-	if (!tls1_check_curve(ctx->ssl, ctx->hs->tls13.server_group))
+	if (!tls1_check_group(ctx->ssl, ctx->hs->tls13.server_group))
 		return 0; /* XXX alert */
 	if (ctx->hs->tls13.server_group == tls_key_share_group(ctx->hs->key_share))
 		return 0; /* XXX alert */
diff --git a/lib/libssl/tls13_server.c b/lib/libssl/tls13_server.c
index 2c1c12ff258..c5c86ab95f5 100644
--- a/lib/libssl/tls13_server.c
+++ b/lib/libssl/tls13_server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls13_server.c,v 1.98 2022/06/04 01:14:43 tb Exp $ */
+/* $OpenBSD: tls13_server.c,v 1.99 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2019, 2020 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2020 Bob Beck <beck@openbsd.org>
@@ -432,9 +432,9 @@ tls13_server_hello_retry_request_send(struct tls13_ctx *ctx, CBB *cbb)
 
 	if (ctx->hs->key_share != NULL)
 		return 0;
-	if ((nid = tls1_get_shared_curve(ctx->ssl)) == NID_undef)
+	if (!tls1_get_supported_group(ctx->ssl, &nid))
 		return 0;
-	if ((ctx->hs->tls13.server_group = tls1_ec_nid2curve_id(nid)) == 0)
+	if (!tls1_ec_nid2group_id(nid, &ctx->hs->tls13.server_group))
 		return 0;
 
 	if (!tls13_server_hello_build(ctx, cbb, 1))
diff --git a/lib/libssl/tls_key_share.c b/lib/libssl/tls_key_share.c
index c170f086495..048db25bd54 100644
--- a/lib/libssl/tls_key_share.c
+++ b/lib/libssl/tls_key_share.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls_key_share.c,v 1.6 2022/07/02 09:33:20 tb Exp $ */
+/* $OpenBSD: tls_key_share.c,v 1.7 2022/07/02 16:00:12 tb Exp $ */
 /*
  * Copyright (c) 2020, 2021 Joel Sing <jsing@openbsd.org>
  *
@@ -61,7 +61,7 @@ tls_key_share_new(uint16_t group_id)
 {
 	int nid;
 
-	if ((nid = tls1_ec_curve_id2nid(group_id)) == NID_undef)
+	if (!tls1_ec_group_id2nid(group_id, &nid))
 		return NULL;
 
 	return tls_key_share_new_internal(nid, group_id);
@@ -73,7 +73,7 @@ tls_key_share_new_nid(int nid)
 	uint16_t group_id = 0;
 
 	if (nid != NID_dhKeyAgreement) {
-		if ((group_id = tls1_ec_nid2curve_id(nid)) == 0)
+		if (!tls1_ec_nid2group_id(nid, &group_id))
 			return NULL;
 	}